Recently, a system to provide a plurality of buildings with an energy saving service via a network is well known. The energy saving service mainly operates for medium and minor scaled buildings as a target. In following explanation, the system to provide the energy saving service is called “an energy saving service provision system”. The energy service provision system is composed by a plurality of servers.
When types of the energy saving service or the number of buildings to utilize the energy saving service increases, computer resources necessary for a server of this system to execute the energy saving service also increases. Here, “computer resource” means a CPU, a memory, a disk, or a network band of the server in the energy saving service provision system. For an operator of the energy saving service provision system, in order to reduce hardware cost, maintenance cost and electric charges, reduction of the computer resource of the server is important.
In order to reduce the computer cost, smoothing of consumption of the computer resource (Hereinafter, it is called “resource consumption”) along time axis is important. In general, the computer resource should be prepared to match with the resource consumption at a peak time. As a result, except for the peak time of the consumption, the computer resource not utilized occurs. Accordingly, if the resource consumption at the peak time can be lowered by smoothing the resource consumption along time axis, the computer resource to be prepared by the energy saving service provision system can be reduced.
As to conventional technique for smoothing the resource consumption, for example, in a load distribution apparatus, by collecting a load status of each server and by transferring an execution program of the energy saving service from a server having high load to another server having low load, smoothing of the load is realized. Here, as to the conventional technique, “load status” means the resource consumption. Accordingly, in a load distribution apparatus thereof, based on information acquired inside the energy saving service provision system, i.e., a load status of the server, smoothing of the load is executed.
However, in the load distribution apparatus thereof, not by using information (related to the energy saving service) outside the energy saving service provision system, smoothing of the load is executed. In other words, an apparatus to smooth the load using external information of the energy saving service provision system does not exist.